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Showing papers on "Radiation mode published in 2010"


Journal ArticleDOI
TL;DR: A kind of plasmonic whispering-gallery mode highly localized on the exterior surface of a metal-coated microresonator that possesses high quality factors at room temperature, and can be efficiently excited by a tapered fiber.
Abstract: We propose a kind of plasmonic whispering-gallery mode highly localized on the exterior surface of a metal-coated microresonator. This exterior (EX) surface mode possesses high quality factors at room temperature, and can be efficiently excited by a tapered fiber. The EX mode can couple to an interior (IN) mode and this coupling produces a strong anticrossing behavior, which not only allows conversion of IN to EX modes, but also forms a long-lived antisymmetric mode. As a potential application, the EX mode could be used for a biosensor with a sensitivity high of up to 500 nm per refraction index unit, a large figure of merit, and a wide detection range.

141 citations


Journal ArticleDOI
TL;DR: An optical fiber refractometer based on a cladding-mode Bragg grating that consists of a long-period grating followed by a fiber Bragggrating and can be multiplexed on a fiber in wavelength domain.
Abstract: We demonstrate an optical fiber refractometer based on a cladding-mode Bragg grating. It consists of a long-period grating (LPG) followed by a fiber Bragg grating (FBG). The LPG partially couples light from the core mode to a cladding mode, both of which are reflected by the FBG. Part of the cladding mode reflection is coupled back to the core mode through the original LPG and used for refractive index sensing. The core mode reflection is used to compensate for the temperature cross sensitivity of the refractometer. The sensors operate in the reflection mode and can be multiplexed on a fiber in wavelength domain.

134 citations


Journal ArticleDOI
TL;DR: A new, efficient adiabatic in-plane fiber-to-chip coupler design that allows to reduce the coupler length multiple times in comparison with pure inverse taper-based couplers of similar efficiency is proposed.
Abstract: A new, efficient adiabatic in-plane fiber-to-chip coupler design is proposed. In this design, the light from the fiber is coupled into a low-index waveguide with matching mode size. The mode is first adiabatically reduced in size with a rib taper, and then transferred into a high-index (e.g. silicon) waveguide with an inverse taper. The two-stage design allows to reduce the coupler length multiple times in comparison with pure inverse taper-based couplers of similar efficiency. The magnitude of length reduction increases with the refractive index of the low-index waveguide and the fiber mode size.

111 citations


Journal ArticleDOI
TL;DR: An efficient and novel optical fiber-to-waveguide mode size converter for Si Photonics devices with sub-micron waveguides is developed on the SOI platform.
Abstract: In this paper, an efficient and novel optical fiber-to-waveguide mode size converter for Si Photonics devices with sub-micron waveguides is developed on the SOI platform. This optical converter is composed of a suspended SiO2 waveguide and overlapped Si nano-tapers located in the center of suspended SiO2 waveguide. Laterally connected SiO2 beams provide structural support for the suspended SiO2 waveguide. The optical input signal from the optical fiber is launched into the suspended SiO2 waveguide, and then coupled into the Si nano-taper. The measured coupling loss using a lensed fiber with 5 µm spot diameter is 1.7 ~2.0 dB/facet for TE mode and 2.0 ~2.4 dB/facet for TM mode in the wavelength range of 1520 ~1600 nm. When a cleaved fiber with 9.2µm spot diameter is used, the coupling losses for both TE and TM modes are less than 4.0 dB/facet at 1550 nm. For the case of lensed fiber, the alignment tolerances for both TE and TM modes are about ± 1.7 µm for 1 dB excess loss in both X and Y axes. The alignment tolerances for both modes of TE and TM are relaxed, exceeding ± 2.5 µm for 1 dB excess loss in both X and Y axes when a cleaved fiber is used.

101 citations


Patent
09 Mar 2010
TL;DR: In this paper, the authors proposed an optical waveguide with a first and second triangular plate-like spot size converter members formed of the same material as a core material and being arranged and formed in a substantially symmetrical structure.
Abstract: An optical waveguide, on account of its ability to apply phase resonance of a wavelength and of a first and second triangular plate-like spot size converter members formed of the same material as a core material and being arranged and formed in a substantially symmetrical structure, can promote shortening of the waveguide length and contrive to reduce the size of the optical waveguide itself. Further, an optical waveguide having excellent spot size conversion efficiency can be obtained even in a reduced size.

84 citations


Journal ArticleDOI
TL;DR: Dispersion characteristics for the low-loss waveguide modes, the linearly-polarized HE(11) mode and the TE(01) mode are obtained, and the experimental results to the metallic waveguide dispersion are compared.
Abstract: Thin dielectric layers deposited on the inner surface of hollow cylindrical metallic waveguides for Terahertz (THz) waves reduce transmission losses below 1 dB/m. Impact of the dielectric layer on the waveguide dispersion is experimentally investigated by near-field mapping of guided short THz pulses at the input and the output of the waveguide. We obtain dispersion characteristics for the low-loss waveguide modes, the linearly-polarized HE11 mode and the TE01 mode, and compare the experimental results to the metallic waveguide dispersion. The additional dispersion due to the dielectric layer is found to be small for the HE11 mode and the phase velocity is primarily determined by the waveguide radius.

79 citations


Proceedings ArticleDOI
TL;DR: In this article, the authors reported the first Silicon/III-V evanescent laser based on adiabatic mode transformers, which is formed by two vertically superimposed waveguides separated by a 100nm-thick SiO2 layer.
Abstract: We report the first Silicon/III-V evanescent laser based on adiabatic mode transformers. The hybrid structure is formed by two vertically superimposed waveguides separated by a 100nm-thick SiO2 layer. The top waveguide, fabricated in an InP/InGaAsP-based heterostructure, serves to provide optical gain, and the bottom Si-waveguides system, which supports all optical functions, is constituted by two tapered rib-waveguides (mode transformers), two distributed Bragg reflectors (DBR), and a surface-grating coupler. The supermode of this hybrid structure is controlled by an appropriate design of the tapers located at the edges of the gain region. In the middle part of the devices, almost all the field resides in the III-V waveguide so that the optical mode experiences maximal gain, while in regions near the III-V facets, mode transformers ensure an efficient transfer of the power flow towards Si-waveguides. The investigated device operates under quasi-continuous wave regime. The room temperature threshold current is 100 mA, the side mode suppression ratio is as high as 20dB, and the fiber-coupled output power is ~7mW.

74 citations


Journal ArticleDOI
TL;DR: Using Fourier optics, it is shown that quasi-phase matching between the third-harmonic signal and the fundamental mode is provided in this geometry by coupling to the continuum of radiation modes above the light line.
Abstract: Using Fourier optics, we retrieve the wavevector dependence of the third-harmonic (green) light generated in a slow light silicon photonic crystal waveguide. We show that quasi-phase matching between the third-harmonic signal and the fundamental mode is provided in this geometry by coupling to the continuum of radiation modes above the light line. This process sustains third-harmonic generation with a relatively high efficiency and a substantial bandwidth limited only by the slow light window of the fundamental mode. The results give us insights into the physics of this nonlinear process in the presence of strong absorption and dispersion at visible wavelengths where bandstructure calculations are problematic. Since the characteristics (e.g. angular pattern) of the third-harmonic light primarily depend on the fundamental mode dispersion, they could be readily engineered.

71 citations


Journal ArticleDOI
TL;DR: A hybrid plasmonic waveguide structure is proposed and fabricated for low-loss lightwave guiding along a metal stripe core by embedding Au stripe in dual slab waveguides with high refractive-index contrast, and the propagation loss is significantly reduced.
Abstract: A hybrid plasmonic waveguide structure is proposed and fabricated for low-loss lightwave guiding along a metal stripe core. By embedding Au stripe in dual slab waveguides with high refractive-index contrast, the field of the guided mode is confined more in the two dielectric core layers. Thus, the propagation loss is significantly reduced. The guided mode is like a combination of a fundamental long-range surface plasmon polariton strip mode and a dual symmetric dielectric slab mode. We fabricate 5 nm-thick Au stripe optical waveguides and measure the optical properties at a wavelength of 1.31 µm. The propagation loss is less than 1.0 dB/cm with the metal stripe width of 1–5 μm.

68 citations


Journal ArticleDOI
TL;DR: In this article, the authors revisited the loss phenomenon for a microstrip patch in reflectarray mode, and discussed the reflection characteristics (magnitude and phase) for a reflectarray element with low and high-loss substrates.
Abstract: This paper revisits the loss phenomenon (particularly, the dielectric loss) for a microstrip patch in reflectarray mode, and discusses the reflection characteristics (magnitude and phase) for a reflectarray element with low- and high-loss substrates. First, the dielectric losses that occur in a lossy slab backed by a perfect electric conductor are both analytically and numerically investigated. Using similar numerical analysis, the reflectarray element (a patch on top of a slab backed by a conductor) is characterized, based on dielectric losses and reflection behavior. It is observed that for low-loss substrates, the dielectric loss decreases with increasing substrate thickness (as previously suggested in the literature). More importantly, for high-loss substrates, the dielectric loss no longer follows the expected trend (decreasing loss with increasing substrate thickness). The dielectric loss becomes a complex phenomenon, involving the dielectric loss tangent and substrate thickness. It is therefore noted that it is important to recognize the well-behaved and misbehaved phase-swing region for high-loss substrates for a reflectarray element. A simple circuit-model representation is provided for the reflectarray element. The anomalous phase behavior observed for high-loss substrates is explained using pole-zero analysis. Waveguide measurements are performed to quantify these reflectarray losses for low- and high-loss substrates. Finally, the loss mechanisms in a patch reflectarray (scattering mode) are compared to a patch antenna (radiation mode), using parameters such as reflection power and radiation efficiency, and similar loss mechanisms for both structures are apparent.

60 citations


Journal ArticleDOI
TL;DR: In this paper, the authors considered the TE10 mode that propagates in an evacuated rectangular waveguide and encounters a plasma which is filled in another waveguide of the same size.
Abstract: Studies on the propagation of high power microwave and its interaction with a plasma in a metallic waveguide are carried out. For this we consider the fundamental TE10 mode that propagates in an evacuated rectangular waveguide and encounters a plasma which is filled in another waveguide of the same size. Using Maxwell’s equations we evaluate the field components of the mode in the evacuated waveguide and then obtain coupled differential equations for the field components of the mode in the plasma filled waveguide, where the plasma effect enters in terms of its dielectric constant. These equations are solved numerically using the fourth-order Runge–Kutta method for the electric field amplitude of the microwave and its wavelength under the effect of plasma density, waveguide width, and microwave frequency. All the investigations are carried out for different initial plasma density profiles, namely homogeneous density, linear density with gradient in the propagation direction and the density with Gaussian pr...

Journal ArticleDOI
TL;DR: In this paper, the fiber is used to direct the excitation light to the waveguide grating structures and to carry the signal response back to the detection system, which is suitable as long-range sensors for the detection of refractive-index changes in nontransparent or toxic liquids.
Abstract: Fabrication and characterization of the miniature device of waveguide grating-structures (WGS) on the end facet of an optical fiber are demonstrated. A layer of ZnO between the fiber and the grating structures serves as the waveguide. The fiber is used to direct the excitation light to the WGS and to carry the signal response back to the detection system. The narrow-band waveguide resonance mode tunable in the visible spectrum can be measured through the fiber in both the transmission and reflection. This nanodevice may be suitable as long-range sensors for the detection of refractive-index changes in nontransparent or toxic liquids.

Journal ArticleDOI
22 Nov 2010
TL;DR: A siliconWaveguide based TE mode converter was designed for the mode conversion between a horizontal waveguide and vertical waveguide in the two-layer structure waveguide based polarization diversity circuit and its performance was studied.
Abstract: A silicon waveguide based TE mode converter was designed for the mode conversion between a horizontal waveguide and vertical waveguide in the two-layer structure waveguide based polarization diversity circuit. The TE mode converter's performance was studied. The polarization mode converter with minimum length of 5μm was demonstrated to provide the TE mode conversion while maintaining the polarization status. The insertion loss at the transition region was less than 3dB.

Patent
22 Jun 2010
TL;DR: In this article, an integrated optical coupler and a method of optically coupling light, between an optical element and at least one integrated optical waveguide, is presented, which is adapted for coupling light to waveguide modes with different polarization with low polarization dependent loss.
Abstract: Disclosed are an integrated optical coupler, and a method of optically coupling light, between an optical element and at least one integrated optical waveguide. The optical coupler includes a grating structure and is adapted for coupling light to waveguide modes with different polarization with low polarization dependent loss. For example, polarization dependent loss may be smaller than 0.5 dB. The waveguide modes may include a Transverse Electric (TE) waveguide mode and a Transverse Magnetic (TM) waveguide mode. The optical coupler may further include a two-dimensional grating structure adapted for providing polarization splitting for a first optical signal of a first predetermined wavelength and for coupling both polarizations forward or backward.

Journal ArticleDOI
TL;DR: In this paper, a different approach based on the acoustic radiation modes of the array is proposed, which leads to a reduced number of active channels, and to minimum source voltages for a given target directivity pattern.
Abstract: This work concerns the theoretical analysis and synthesis of sound fields by a compact spherical loudspeaker array. Such an electroacoustic device consists of several transducers mounted on a sphere-like structure, which are driven independently in order to achieve non-uniform directivity patterns. The control strategy usually adopted is to provide the array with some preprogrammed basic directivities corresponding to spherical harmonic functions. Thus, an arbitrary radiation pattern can be approximately achieved by changing the gains associated with these basic directivities. Here, a different approach based on the acoustic radiation modes of the array is proposed. Unlike spherical harmonics, radiation modes constitute a finite set of vectors that spans a subspace on which any radiation pattern the array is able to reproduce can be projected. Furthermore, radiation modes radiate sound energy independently. Since the eigenvalue analysis that must be carried out in order to obtain the modes leads also to their radiation efficiencies, the low frequency constraint in the directivity synthesis by a spherical array is naturally evaluated. Finally, it is useless to drive inefficient radiation modes. Therefore, the radiation mode approach leads to a reduced number of active channels, and to minimum source voltages for a given target directivity pattern.

Proceedings ArticleDOI
12 Feb 2010
TL;DR: In this paper, the performance of two types of edge emitting lasers with unconventional waveguides and lateral arrays thereof is evaluated, and the results on coherent coupling of several lasers are presented.
Abstract: We have designed, fabricated and measured the performance of two types of edge emitting lasers with unconventional waveguides and lateral arrays thereof. Both designs provide high power and low divergence in the fast and the slow axis, and hence an increased brightness. The devices are extremely promising for new laser systems required for many scientific and commercial applications. In the first approach we use a broad photonic crystal waveguide with an embedded higher order mode filter, allowing us to expand the ground mode across the entire waveguide. A very narrow vertical far field of ~ 7° is resulting. 980 nm single mode lasers show in continuous wave operation more than 2 W, ηwp ~ 60%, M2 ~ 1.5, beam parameter product of 0.47 mm×mrad and a brightness ~ 1×108 Wsr-1cm-2 respectively. First results on coherent coupling of several lasers are presented. In the second approach we use leaky designs with feedback. The mode leaks from a conventional waveguide into a transparent substrate and reflects back, such that only one mode at a selected wavelength is enhanced and builds up, others are suppressed by interference. 1060 nm range devices demonstrate an extremely narrow vertical far field divergence of less than 1°.

Journal ArticleDOI
TL;DR: Guiding properties of nanoscale metallic wire waveguides embedded in a semiconductor are discussed and comprehensive mode characteristics, such as the effective refractive index, effective mode area, and propagation length, that provide full guided mode description are obtained.
Abstract: Guiding properties of nanoscale metallic wire waveguides embedded in a semiconductor are discussed. By performing eigenmode numerical simulations of the waveguide and continually varying the geometrical cross-section parameters, we have obtained comprehensive mode characteristics, such as the effective refractive index, effective mode area, and propagation length, that provide full guided mode description. This allows us to gain insight into possible waveguide applications using the figures of merit. Amplification and polarization manipulation of a plasmonic signal in such a waveguide have also been considered.

Patent
21 Sep 2010
TL;DR: In this article, a system configured to generate an optical beam from a fiber laser is presented, which includes a fiber gain medium having a core and a cladding, the core being configured to convert radiation from a pump beam into an output beam, the cladding having a mode propagating section and a mode stripping section bounded on a near end and a distal end by the mode propagation section.
Abstract: A system configured to generate an optical beam from a fiber laser is presented. The system includes a fiber gain medium having a core and a cladding, the core being configured to convert radiation from a pump beam into an output beam, the cladding having a mode propagating section and a mode stripping section bounded on a near end and a distal end by the mode propagating section, the mode stripping section of the cladding being configured to scatter excess pump radiation received from the mode propagating section in a substantially outwardly radial direction. The system also includes a rigid support member into which the fiber gain medium is placed, the rigid support member completely encompassing the mode stripping section of the cladding and joined to the fiber at the mode propagating section of the cladding.

Journal ArticleDOI
TL;DR: In this article, a finite thickness metal-insulator-metal (f-MIM) structure was proposed to enhance the coupling between the surface plasmon-polariton (SPP) and optical waves propagating along dielectric waveguides.
Abstract: As a solution to enhance the coupling between the surface plasmon-polariton (SPP) and optical waves propagating along dielectric waveguides, we present the finite thickness metal-insulator-metal (f-MIM) structure. Achieving such opto-plasmonic coupling has been difficult due to the inherent difference in the two waves’ dispersion characteristics. The f-MIM provides an effective way to tune the dispersion characteristics of its SPP mode to match those of the waveguide modes. The resultant enhancement in mode coupling enables waveguide-based excitation of SPPs, which, in turn, leads to the realization of integrated optic surface plasmon resonance (SPR) sensors. Our simulations showed that the effective index of the f-MIM's SPP mode can be increased to match those of typical dielectric waveguide modes even when the f-MIM itself was surrounded by low-index material such as water ( n = 1.33). Moreover, the SPP's mode profile can also be controlled simultaneously to exhibit its peak at the interface with the analyte. All these characteristics render the f-MIM an ideal element for waveguide-based SPR sensing in aqueous environment. By integrating the f-MIM with a polymer waveguide, we obtained SPR sensing resolutions of 1.53 × 10 −5 in RIU and 0.016 nm in thickness in refractometric and affinity sensing modes, respectively.

Journal ArticleDOI
TL;DR: In this article, an electrically controlled waveguide mode for optical beams propagating in the plane of a liquid crystal (LC) layer is described, which is based on the total internal reflection of light beams from two parallel boundaries, which separates the regions of the liquid crystal cell with different orientation and refractive indices.

Journal ArticleDOI
TL;DR: In this article, the authors measured the complex electric field at the waveguide end from the measured temperature profiles and found that the mode content had small dependence on the length of the transmission line.
Abstract: The preliminary results of mode measurement in the ITER relevant 40 m long transmission test line composed from 63.5 mm diameter corrugated waveguides and miter bends are presented. The field patterns were measured by taking temperature profiles on a paper screen placed in front of the waveguide end using an infrared imaging camera. The complex electric field at the waveguide end was retrieved from the measured temperature profiles. As a result, the transmission power includes 87% of HE11 mode and 6% of LP11 odd (HE21+TE01) mode and small ratios of other modes. The mode content had small dependence on length of the transmission line. This result indicated that the higher order mode content generated at the input of the transmission line is conserved and propagated through the transmission line. This suggests that the initial RF coupling to the waveguide is critical since it affects the launcher efficiency.

Journal ArticleDOI
TL;DR: In this article, the asymmetric versus symmetric planar waveguide in terms of their usefulness in optical fiber communication systems was studied and the power confinement properties for symmetric as well as asymmetric waveguide structure were compared.
Abstract: In this paper we have studied the asymmetric versus symmetric planar waveguide in terms of their usefulness in optical fiber communication systems. We have explored the thin waveguide versus thick waveguide first. Later on usefulness of asymmetric versus symmetric waveguide is carried out to target for WDM optical network application. All kinds of optical network components are fabricated on Si substrate with the point of view of their application. Here asymmetric planar structure may be more useful compared to symmetric waveguide in terms of their non-uniform power confinement properties. However, the symmetric waveguide structure may be more useful for their high power confinement properties. It is well known that the thin symmetric waveguide supports at least one mode. However the thick waveguide may support many even as well as odd modes. We study the power confinement properties for symmetric as well as asymmetric waveguide structure. We conclude that higher order modes show the nonlinear power variations. Mode field profile for various cases is discussed as well. Comparative study between asymmetric versus symmetric waveguide has a lot of significance in optical network area. It has been shown through analysis that in asymmetric waveguide, the power flows more through film region in the case of fundamental mode. Power confinement properties for asymmetric waveguide versus symmetric waveguide have been studied.

Journal ArticleDOI
TL;DR: Hybrid large mode area Ytterbium-doped double-cladding photonic crystal fibers with anti-symmetric high refractive index inclusions provide efficient amplified spontaneous emission spectral filtering.
Abstract: Hybrid large mode area Ytterbium-doped double-cladding photonic crystal fibers with anti-symmetric high refractive index inclusions provide efficient amplified spontaneous emission spectral filtering. Their performances have been analyzed by numerical simulations and experimental measurements. In particular, the fiber single-mode behaviour has been studied, by taking into account the fundamental and the first higher-order mode. Two approaches, the core down-doping and the reduction of the air-hole diameter in the inner cladding, have been successfully applied to reduce the higher-order mode content, regardless of the bending of the doped fiber, without significantly affecting its spectral filtering properties.

Journal ArticleDOI
TL;DR: The principle, applicability and accuracy of the approximations are demonstrated, and the detailed implementation is suggested by applying a unified coupled-mode analysis to fiber gratings and the simulated results agree well with those obtained theoretically and experimentally.
Abstract: To facilitate the analysis of radiation mode couplings, quasi leaky mode approximations were utilized in coupled-mode analysis. The key to effectively and accurately apply this approach is how to well approximate radiation modes by the quasi leaky modes in an equivalent closed waveguide model. In this paper, the principle, applicability and accuracy of the approximations are demonstrated, and the detailed implementation is also suggested by applying a unified coupled-mode analysis to fiber gratings. First of all, based on a thorough study on the characteristics of the complex modes, for the first time, quasi leaky modes are classified into guided-mode-like inner-cladding and radiation-mode-like outer-cladding leaky modes so as to explicitly establish equivalence relationships between the discrete leaky modes and the continuous radiation modes. With this new insight, the whole analysis process especially for some of the practically tricky issues such as the criteria for developing the proper equivalent waveguide model and the subsequent mode expansion basis are better understood and easier to be dealt with for different problems where radiation modes come into play. Moreover, as essential preconditions to extend the conventional coupled mode analysis to the present unified one, the couplings between the guided core mode and a leaky mode are studied in a systematic and consistent manner. An intuitive and then a deep understanding on the roles of complex modes on mode coupling and power exchanging are thus gained for further simulations. Lastly, the transmission spectra of fiber gratings with different surrounding indices are simulated. The simulated results agree well with those obtained theoretically and experimentally in the literatures, which strongly validate the principle of quasi leaky mode approximations and its implementation on the unified coupled-mode analysis expounded in this paper.

Journal ArticleDOI
TL;DR: Simulation results show that hybridization of the single-wire mode and the gap plasmon mode can yield a hybrid mode with optimum propagation lengths comparable to those reported for other structures but with better light confinement.
Abstract: We propose the inclusion of a structured pattern of nanoscale metal wires in a silica fiber to form a symmetric plasmonic waveguide. The surface plasmon polariton modes within the waveguide are studied by varying the wire diameter and spacing. Simulation results show that hybridization of the single-wire mode and the gap plasmon mode can yield a hybrid mode with optimum propagation lengths comparable to those reported for other structures but with better light confinement. The fiber can be easily doped with a gain material to offset the loss so that the resultant waveguide will be useful for integration with electronic circuits at nanometer dimensions.

Proceedings ArticleDOI
04 Nov 2010
TL;DR: In this paper, stable MIMO transport of three channels over a two-mode fiber was shown in the presence of fiber bending induced mode coupling, enabled by a new adiabatic mode splitter output coupler.
Abstract: Simulations confirm stable MIMO transport of three channels over a two mode fiber — even in the presence of fiber bending induced mode coupling — enabled by a new adiabatic mode splitter output coupler.

Journal ArticleDOI
Jaehoon Jung1
TL;DR: In this paper, a dielectric-loaded surface plasmon polariton waveguide using a genetic algorithm is proposed, which consists of a polymer ridge on top of two layers of substrate and gold film, and the thickness, width and refractive index of the ridge are designed to optimize the figures of merit including mode confinement and propagation length.
Abstract: We propose a design and optimization method for a dielectric-loaded surface plasmon polariton waveguide using a genetic algorithm This structure consists of a polymer ridge on top of two layers of substrate and gold film The thickness, width and refractive index of the ridge are designed to optimize the figures of merit including mode confinement and propagation length The modal analysis combined with the effective index method shows that the designed waveguide exhibits a fundamental propagation mode with high mode confinement while ensuring that the propagation loss remains relatively low

Patent
Babak Amirparviz1
05 Nov 2010
TL;DR: In this article, a waveguide suitable in form factor and weight for use in a heads-up display or similar wearable display and a method of manufacturing the waveguide is disclosed.
Abstract: A waveguide suitable in form factor and weight for use in a heads-up display or similar wearable display and a method of manufacturing the waveguide are disclosed. The waveguide comprises a waveguide body of light-weight, optically transparent solid material, such as plastic, with a series of micro structures embedded in the waveguide body at a top surface of the waveguide body. A first set of the micro structures near one end of the waveguide body serves to couple light into the waveguide, whereby a portion of the coupled light propagates subject to total internal reflection toward a second set of micro structures that reflects a portion of the propagated light out of the waveguide at a bottom surface of the waveguide body. The waveguide can deliver an image provided by an input light source to a human eye (or other detector) situated near the bottom surface of the waveguide body. In particular, the source image can be focused at infinity so that it appears in focus as viewed by the eye at the output of the waveguide. Methods for simple and inexpensive mass production of the waveguide are also disclosed.

Journal ArticleDOI
TL;DR: A novel structure of SPSM photonic crystal fibers based on the resonant coupling phenomena is proposed and analyzed by using a full-vector finite-element method with a second-order transparent boundary condition.
Abstract: Single-polarization single-mode (SPSM) fiber can efficiently eliminate polarization mode coupling, polarization mode dispersion, and polarization-dependent loss. Up to now, most single-polarization fibers have been designed based on form birefringence, which would result in a non-Gaussian field distribution and a small effective mode field area. In this paper, a novel structure of SPSM photonic crystal fibers based on the resonant coupling phenomena is proposed and analyzed by using a full-vector finite-element method with a second-order transparent boundary condition. From the numerical results it is confirmed that this fiber has a near-Gaussian mode field within the wavelength range from 1.46 to 2.2μm, where only one polarized mode exists effectively, and the mode field area is about 79μm2 at the wavelength of 1.55μm, matching that of the conventional single-mode fiber.

Journal ArticleDOI
TL;DR: In this article, a review of recent work by the authors in which the lowest-order transverse-electric (TE 1 ) mode of a parallel-plate waveguide (PPWG) is used for terahertz (THz) applications is presented.
Abstract: Presented is a review of recent work by the authors in which the lowest-order transverse-electric (TE 1 ) mode of a parallel-plate waveguide (PPWG) is used for terahertz (THz) applications. This work adds a new dimension to the multitude of diverse THz applications made possible by PPWGs. Using the TE 1 mode, demonstration is presented of an ultra-low loss THz waveguide, a highly sensitive microfluidic sensor, a whispering-gallery mode waveguide, and an artificial dielectric with an effective refractive index less than unity.